Adderall is widely prescribed to treat Attention Deficit Hyperactivity Disorder (ADHD) and narcolepsy. It improves focus, attention, and impulse control, but if you take Adderall. You might be wondering: How long does Adderall stay in your system? Usually, it stays in three days in the system, but in certain cases it’s influenced by many factors. Thus, various drug tests can detect Adderall within different time frames.